Air cooled internal combustion engine



Sept. 8, 1959 oss 2,902,985

AIR COOLED INTERNAL COMBUSTION ENGINE Filed Jan. 16, 1958 2 Sheets-Sheet 1 FIG-I i Sept. 8, 1959 R. KLOSS 2,902,985

AIR COOLED INTERNAL COMBUSTION ENGINE Filed Jan. 16. 1958 2 Shets-Sheet 2 INVENTUP fiyarq/y/aJs 43kg 4 United States Patent AIR COOLED INTERNAL CONIBUSTION ENGINE Richard Kloss, Koln-Buchforst, Germany, assignor to Klockner-Humboldt-Deutz Aktiengesellschaft, Koln, Germany Application January 16, 1958, Serial No. 709,384 Claims priority, application Germany January 29, 1957 6 Claims. (Cl. 123-41.05)

The present invention relates to an air-cooled internal combustion engine, especially self-igniting fuel injection engine, with a blower driven by the engine through a transmission of variable transmission ratio, for instance a hydraulic coupling, in which said blower is adapted to feed cooling air toor withdraw cooling air from the engine,'while the delivery of said blower during operation of the engine is controlled by a thermostat arranged in the path of the cooling air flowing away from the engine and adapted to control the transmission ratio of said transmission in conformity with the heated cooling air and thereby indirectly in conformity with the temperature of the engine. Self-igniting fuel injection engines, due to a desired short ignition lag and low wear must possibly be operated in such a way that the engine when being started will quickly reach normal temperature of operation and will also when under partial load, and particularly when running idle over a longer period of .time, re main sutficienlty hot. Furthermore, it is desired that the engine will not cool off too fast after it has been stopped. It is particularly important that the above mentioned requirements be met with the so-called multi-fuel engines, i.e. with such fuel injection engines which may be operated selectively with diesel fuel or with fuels which are considerably more difficult to ignite. The last mentioned fuels include all petroleum distillates obtained up to about 200 C., ie the so-called Otto fuels.

It with an air-cooled self-igniting fuel injection engine, the control of the cooling air is governed by a thermostat arranged in the path of the heated-up cooling air flowing away from the engine, a temperature control of the engine in conformity with the above mentioned requirements is not always possible inasmuch as the delivery of cooling air must never be totally interrupted in order to assure that the thermostat is always acted upon by heated cooling air and is always ready to eflect its control. If the delivery of cooling air is interrupted for a longer time, such engine becomes unduly hot. On the other hand, when maintaining a low delivery of cooling air under low load when idling or when driving downhill, there exists the danger that the engine will cool off too much.

It is, therefore, an object of the present invention to provide a fuel injection engine of the above mentioned type, in which the drawbacks referred to above will be avoided.

It is another object of this invention to provide an air- .cooled fuel injection internal combustion engine, in which the blower for the cooling air may under the above mentioned conditions of operation be stopped [without incurring the above outlined drawbacks.

, It is also an object of this invention to provide a f e injection internal combustion engine of the type set forth in the preceding paragraphs as driving engine for a vehicle, in which the control of the cooling air will not be harmfully affected by the wind encountered during the driving of the vehicle or by strong wind prevailing while the vehicle is at a stop.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing, in which:

Fig. 1 diagrammatically illustrates a top view of an engine according to the present invention.

Fig. 2 is a side view of Fig. 1.

Fig. 3 illustrates the engine of Fig. l as seen in the direction of the arrow A of Fig. 1.

Fig. 4 diagrammatically shows a special driving arrangement for the blower of the engine according to Figs. 1 to 3.

General arrangement The arrangement according to the present invention is characterized primarily in that in addition to the normal cooling air delivering blower there is provided a second or auxiliary cooling air delivering blower of considerably less output than said first mentioned or main blower, while said second or auxiliary blower is driven directly by the engine and delivers heated-up cooling air to or by the thermostat. Such an arrangement brings about that the thermostat will also after the main blower has been stopped remain ready for action at any time. In other words, the thermostat will react and again start the main blower as soon as the engine temperature exceeds a certain permissible temperature. The auxiliary blower may be driven through the intervention of any suitable shaft of the engine. In conformity with the present invention, the auxiliary blower may be driven for instance by the same shaft which drives the main blower through a transmission. In the last instance, the transmission preceding the main blower and the auxiliary blower may be combined to a single structural unit. To this end, for instance, the slip coupling element adjacent the engine may be equipped with blades while the rotor forms the auxiliary blower. At any rate the auxiliary blower can be of very simple design.

When employing an engine according to the present invention on vehicles, it should be kept in mind that also with the main blower at a standstill, the control effect to be produced in conformity with the present invention may entirely or partly be affected when the engine is mounted on a vehicle encountering considerable wind during the driving of the vehicle or while said vehicle is at a standstill. In order to overcome such undesired interference, according to the present invention there is provided a throttle either in front or behind the main blower. Such throttle may, for instance, be in the form of louvers which may either selectively be closed by hand or may close automatically when the main blower is stopped. Within the ambit of the present invention, such throttle may be of any desired design and may be actuated in any suitable manner. Thus, for instance, the control of the throttle may be efiected in conformity with the static pressure produced by the main blower or by the dynamic pressure behind said last mentioned blower. It is also possible to control the throttle by a transmission preceding the blower or by the thermostat in the cooling air flowing off from the engine, or by the accelerator.

With the main blower at a standstill and the auxiliary blower in operation, it may occur that during a longer downhill drive of a vehicle equipped with an engine according to the invention, not the engine temperature but the temperature of the lubricating oil becomes unduly high so as to require a certain quantity of cooling air. In order to meet such a condition, in other words in order to assure that the thermostat remains ready for action under such condition, it is suggested according to the invention that either all of the air or a part of the air conveyed by the auxiliary blower to the thermostat also be passed through the oil cooler of the engine so that the thermostat indirectlyalso controls the temperature of the I Referringnow to the drawing indetaiL the engine illustrated. in Fig. 1: is an eighhcylihder, air-cooled internal combustion engine comprising two groups of four cylinders each, the cylinders 1, 2, 3, 4 forming one group and the cylinders; 5, 6,, 7, 8 formingthe other group. The two groups are arranged relative to each other in V.-formation. The cooling air for cooling the engine is furnished by a blower 11, which is arranged atone endof the engine and is driven by the latter through the interventio f, a shaft 9 and a hydraulic fluid coupling 10. The blower delivers. thecooling air into the V,-space 12 between the two cylinder groups 1, 2, 3, 4 and 5, 6, 7, 8. The thus delivered cooling air flows from said V-space to the various portions of the engine to be cooled. As will be evident from the drawing, the driving shaft 9: for the blower L1: is: substantially parallel to the crank shaft 13 inthe V-space 12. Adjacent the cylinder there is-provided' a cooler 14 for cooling the lubricating oil.

When looking in the direction of'flow of the cooling air, behind the oil cooler 14 and-the cylinder 5, i.e. in the flow of the heated-up flowing-off cooling air there is. arranged a thermostat 15 which through the intervention ofa rod 16 actuates a valve spool 18: reciprocable in a valve casing 19. The said valve spool 18 controls the flow of oil under pressure in conduit- 17 to the fluid: transmission 10, thereby controlling the slippage and thus the speed of the transmission 10. Inasmuch as the blower 11 is driven by the transmission 10, the thermostat 15' thus controls the speed of the blower 11, which latteris provided with an overflow conduit 20, in such a way that a favorable engine temperature is maintained throughout the entire load range. In order to assure, that the thermostat 15 will be acted upon and readyfor action also when the blower 11 is at a standstill, which may occur during idling over a longer period of time or at low load of the engine in order to avoid overcooling, shaft 9 has connected thereto an auxiliary blower 21 of low output. The auxiliary blower 21 will during the operation of the engine deliver cooling air through the oil. cooler 14' and the cooling zone of the cylinder 5 also-when the blower 11 is at a standstill. The rotor 22 of the auxiliary blower 21 forms oneportion of an elastic coupling 23 which precedes the transmission. 10. A throttle 24 designed in the form of louvers is arranged in front of the main blower 11 and is adapted to be closed when the blower 1-1 is at a standstill. In this way, i.e. by closing the throttle 24, a too intense cooling of the engine is prevented which may otherwise be brought about when the engine is mounted on a vehicle which encounters considerable wind during its driving or which encounters strong wind while the vehicle is at a standstill. If such undue cooling were not prevented, the control effect to be brought about in conformity with the invention by the arrangement ofthe auxiliary blower might entirely or partially be undone or counteracted. The engine is furthermore provided with a fly-wheel 25.

Referring now to Fig. 4, this figure illustrates a modification of the hydraulic fluid coupling or transmission and the auxiliary blower. According to Fig. 4, the hydraulic fluid coupling is so designed that its housing 26 forms one portion of the coupling and thus rotates together with the drive shaft 9 and the elastic coupling 23. The housing 26 of the fluid coupling has that side thereof which is adjacent the engine equipped with blades 27 and while further extending into the V-space 12 of the engine forms the rotor of the auxiliary blower according to the invention.

Itis, of course, to be understood that the present invention is, by no means, limited to the particularconstructions. shown in the drawing but also comprises any modifications within the scope of the appended claims.

Thus, while highly satisfactory results have been ob- 4 tained if the output of the auxiliary blower is about & of. that of the main. blower, also. other ratios. may. be selected.

What I claim is:

1. In combination with an air-cooled fuel injection engine: a main cooling air blower; a transmission having a variable transmission ratio anddrivingly connecting said blower with said; engine; a thermostat arrangedin, the path of cooling air heated up by and flowing off from said; engine and controlled by said; main; blower; said thermostat being operatively connected to said; transmission to control the transmission ratio thereof, and thereby also, he el v y ofi a dimain blq terain. cnnformity with the temperature of the cooling air passing by saidthermostat; and an auxiliary cooling airblower having an output considerably less; than that of; said main blower and being directly drivingly connected to said engine for conveying cooling air heated up by said engine to said thermostat.

2. An arrangement according tolclaim 11, in. which the drive of both of said blowers is effected through one and the same shaft of said engine.

3,. In combination with. an air-cooled; fuel injection engine: a main cooling air blower; a transmission having a variable transmission ratio and having a rotatable member drivingly connected to said blower andto-said engine; a thermostat arranged in the path of cooling air heated up. by and flowing off from said engine and controlled by said main. blower; said thermostat being'operatively connected to said transmission tocontrol the transmission ratio thereof, and thereby also the delivery of said main blower, in conformity: with the temperature of the cooling air passing by said thermostate; and an auxiliary cooling air blower having an output considerably less than that of said main blower and being directly drivingly connected to said engine for conveying cooling air heated up by said engine to saidthermostat; said rotatable member of said transmission also forming a structural partof said second blower.

4; In combination with an air-cooled fuel injection on gine: a main cooling air blower; a slippage couplingar: ranged ahead of said main coolingair'blower-andincluding a housing drivingly connected with said blower and with said engine; a thermostat arranged in the path of cooling air heated up by and flowingolf from said engine and controlled by said main blower; said thermostat being operatively connected to saidslippage coupling to control the slippage thereof, and thereby also the delivery of said main blower, in conformity with the temperature of the cooling air passing by said thermostat; andan auxiliary cooling air blower having an out-put considerably less, than that of said main blower and being directly drivingly connected to said engine for conveying'coolin g air heated up by said engine to said thermostat, said housing of said slippage coupling being provided with blades and; serving as rotor of said auxiliary cooling air; blower.

5. In combination with an air-cooled fuel injection engine; a main cooling air blower; a transmission having a variable transmission ratio and drivingly connecting said blower with said engine; a thermostat arranged in thepath of cooling air heated up by and flowing off, from said engine and controlled by said main blower; said thermostat being operatively connected to said transmission to. control the transmission ratio thereof, and thereby also the, de livery of said main blower, in conformity. with the temperature of the cooling air passing by said; thermostat; throttle means associated with said main blower and adapted selectively to be closed for preventing the flow of air through and from said main blower to said engine; and an auxiliary cooling air blower having an output con; siderably less than that of said main blower being directly drivingly connected to said engine for conveying cooling air heated up by said engine to said: thermostat.

6. In combination with an air-cooled fuel injection engine having a lubricating oil system; a main cooling blower; a transmission having a variable transmission ratio and drivingly connecting said blower with said engine; a thermostat arranged in the path of cooling air heated up by and flowing olf from said engine and controlled by said main blower; said thermostat being operatively connected to said transmission to control the transmission ratio thereof, and thereby also the delivery of said main blower, in conformity with the temperature of the cooling air passing by said thermostat; an auxiliary cooling air blower having an output considerably less 6 than that of said main blower and being directly drivingly connected to said engine for conveying cooling air heated up by said engine to said thermostat, and an oil cooler connected with the lubricating oil system of said engine for cooling the same, said oil cooler being so arranged that at least a portion of the heated-up cooling air delivered by said auxiliary cooling air blower passes by at least a portion of said oil cooler.

No references cited. 

